2. Women of childbearing potential (WOCBP) must have a negative serum or urine pregnancy test (minimum sensitivity 25 IU/L or equivalent units of HCG) prior to enrollment, and agree to using an adequate method of contraception to avoid pregnancy for a period of 6 months beginning from first dose of randomized treatment. WOCBP include any female who has experienced menarche and who has not undergone successful surgical sterilization (hysterectomy, bilateral tubal ligation, or bilateral oophorectomy) or is not postmenopausal. Adequate methods of contraception are practicing complete abstinence from intercourse for two weeks prior to administration of study drug; having a male sexual partner(s) who is surgically sterilized (vasectomy with documentation of azoospermia) prior to inclusion; having a sexual partner(s) who is/are exclusively female; using oral contraceptives (either combined or progestogen only) with single-barrier method of contraception consisting of spermicide and condom or diaphragm; using double-barrier contraception, specifically, a condom plus spermicide and a female diaphragm or cervical cap; using an approved intrauterine device (IUD) with established efficacy.